NASRDiff

A diff report generator for the FAA NASR. NASRDiff parses the files in the 28 Day Cycle CSV Change Report Files product, generating a report for any additions, modifications, and deletions.

By adding a filters.json in the project root, the parser will filter the reports for the specified files, airports or heliports within those files, and/or a bounding box for items that are not specified by airport/heliport ID. An example_filters.json is present in the project root as a template.

Airport Base:
  Modifications:
    APH ::
        ARPT_NAME Change: MARY WALKER LZ -> AP HILL LZ (FORT AP HILL)
    FBG ::
        CITY Change: FORT LIBERTY -> FORT BRAGG
    LBT ::
        FUEL_TYPES Change: 100LL,A1+ -> 100LL,A1+,MOGAS
    MTN ::
        LAT_SEC Change: 32.381 -> 32.374
        LAT_DECIMAL Change: 39.32566138 -> 39.32565944
        LONG_SEC Change: 49.522 -> 49.545
        LONG_DECIMAL Change: -76.41375611 -> -76.4137625
        ELEV Change: 21.5 -> 22.2
        POSITION_SRC_DATE Change: 2011/04/21 -> 2024/11/22
        ELEVATION_SRC_DATE Change: 2011/04/21 -> 2024/11/22
    OBI ::
        LAST_INSPECTION Change: 2024/08/27 -> 2025/09/04
    OKV ::
        LAST_INSPECTION Change: 2022/06/28 -> 2025/09/11
    PHF ::
        LAST_INSPECTION Change: 2022/03/28 -> 2025/09/08
    PVG ::
        LAST_INSPECTION Change: 2022/06/06 -> 2025/08/26
    RMN ::
        LAST_INSPECTION Change: 2022/09/26 -> 2025/07/31
    VA39 ::
        ARPT_NAME Change: FORT GREGG-ADAMS AHP -> FORT LEE AHP

Fix Base:
  No changes

Navigation Base:
  No changes

Requirements

• Python 3.11+

Quick Start

• Clone this repository to a location of your choice using:
  • HTTPS: https://github.com/misterrodg/NASRDiff.git
  • SSH: git@github.com:misterrodg/NASRDiff.git
• Download the 28 Day Cycle CSV Change Report Files from the Current or Preview page of the FAA NASR page.
• Run with python3 main.py -f text
• View the resulting report files in the ./reports directory.

For more detail and options, see Usage.

Usage

To find the NASR Change Report, go to the FAA NASR page, select the Current or Preview page, search for 28 Day Cycle CSV Change Report Files, and download the ZIP file. Since the Current and Preview pages have dates in the URL, it cannot be linked directly.

• Unzip the 28 Day Cycle CSV Change Report Files and copy the .csv files into the navdata directory.
• Copy the example_filters.json as filters.json.
• Edit the filters.json to include the files, airports, and bounds of your choice (see Filters, below).
• Run with python3 main.py [args] (see Arguments, below).

By default, a summary will be printed to the console. If a format is specified as an argument, the resulting reports will be in the reports directory.

Arguments

Short	Long	Action
-a	--all	Run for all files and all file content (ignores the filters.json).
-c	--clear	Clear files from navdata dir.
-f	--format	Sets the report format with options console (default) or text.
-n	--norun	Skip report generation.
-p	--purge	Purge files from reports dir.
-s	--show	Show filters in console.
-v	--verbose	Show record details.

Filters

Field	Description
files	An array of strings representing the initial part of a change report filename (everything up to _CHG_RPT.csv). Set this to select the files that contain data that you are interested in.
bounds	An object with the next four fields.
n_lat	The northernmost latitude boundary in decimal form.
s_lat	The southernmost latitude boundary in decimal form.
w_lon	The westernmost longitude boundary in decimal form.
e_lon	The easternmost longitude boundary in decimal form.
artccs	An array of strings representing the ARTCC code of the ARTCCs that you are interested in.
airports	An array of strings representing the FAA code* of the airports (and heliports) that you are interested in.
airways	An array of strings representing the Airway ID of the airways that you are interested in.

* The FAA Code is a three-letter identifier, commonly mistaken for an IATA code since they are usually the same. Generally, it is the ICAO code without the initial K. There are some oddities that exist, such as Manassas, VA, which uses ICAO: KHEF, FAA: HEF, and IATA: MNZ. If you are unsure, download the full NASR product, open the APT_BASE.csv file, and search for the facility by name. Use the value from the ARPT_ID in the airports array.

Example

The example provided in example_filters.json sets filters for:

• files: "APT_BASE", "FIX_BASE" and "NAV_BASE". This selects only these three files. The rest are ignored.
• bounds: "n_lat": 40.1, "s_lat": 32.9, "w_lon": -80.8, and "e_lon": -72.5. This selects anything defined by a lat/lon position in the area that is shown in the image below.
• artccs: "ZDC". This selects only this ARTCC. The rest are ignored.
• airports: "ADW", "BWI", "DCA", and "IAD". This selects only these airports. The rest are ignored.
• airways: "J110", "J149", "J162", "J211". This selects only these airways. The rest are ignored.

Motivation

Aviation data has the potential to change every 28 days. The FAA has thankfully provided the files that contain only the changed between each cycle, but those files contain every change across the National Airspace System (NAS). Having a utility to filter those changes down to only what is relevant helps you save time and stay up to date.

I made this primarily for myself, but it can be used by anyone who has an interest in aviation data and a basic understanding of python.

Contributing

Interested in helping make this project better? It's a small project, so the process is rather informal:

• Clone this repo to your development machine.
• Make your changes in a branch.
• Open a PR with your suggested changes.

Need ideas on what needs work? Have a look at the Issues page.